1. Field of the Invention
The present invention relates to a motor driver apparatus and a method of controlling the motor driver apparatus.
2. Description of the Related Art
FIG. 6 illustrates a structure of an exemplary motor driver apparatus. Referring to FIG. 6, a motor driver apparatus 10 is attached to and is used for an electric instrument 11. A direct-current power source 12 and an integrated circuit (IC) 13 are provided inside the electric instrument 11. The terminals 14 and 15 are connected with a positive terminal of the direct-current power source 12 and a negative terminal of the direct-current power source 12, respectively.
The motor driver apparatus 10 includes a motor driver IC 20. The terminals 14 and 15 are connected with a power terminal having VDD of the motor driver IC 20 and a ground terminal having GND of the motor driver IC 20. The motor driver IC 20 causes an electric current to flow through a winding wire of a motor 23 whose both terminals are connected with the terminals 21 and 22 through n-channel MOS transistors M1 to M4 thereby driving to rotate the direct current motor 23.
A first state where the MOS transistors M1 and M4 are turned on and the MOS transistors M2 and M3 are turned off to cause a current to flow through the direct-current motor 23 in a direction from the terminal 21 to the terminal 22 and a second state where the MOS transistors M2 and M3 are turned on and the MOS transistors M1 and M4 are turned off to cause the current to flow through the direct-current motor 23 in a direction from the terminal 22 to the terminal 21 are alternately switched over to rotate the direct-current motor. In order to obtain the above-described switch timing, a detection element (not illustrated) having a rotational phase such as a hall element is used.
For example, an exemplary motor driving apparatus is proposed in Japanese Laid-open Patent Application No. 2009-278734.